Currently, there are remote controllers that include a piezoelectric device and do require a battery. For example, Japanese Unexamined Patent Application Publication No. 2011-103729 (Patent Document 1) discloses a configuration of a remote controller which has a power generation capability and which, after detecting that an input unit depressed by the finger of a user has recovered, executes an input command. The remote controller converts AC power generated when the input unit is depressed and when the input unit recovers therefrom into DC power by using a rectifier unit, and stores the DC power in a power storage unit (capacitor). Moreover, Japanese Unexamined Patent Application Publication No. 2004-201376 (Patent Document 2) discloses a configuration in which AC power generated by letting the free end of an actuator freely vibrate is converted into DC power by a rectifier.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2011-103729.
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2004-201376.
In Patent Document 1 and Patent Document 2, a charge generated by a piezoelectric device is rectified by a full-wave rectifier circuit and provided to a capacitor serving as a power storage unit. With respect to a reference potential which is a potential in a state in which the piezoelectric device is not deformed, a full-wave rectifier circuit can supply to a subsequent circuit both a charge generated at a positive potential obtained as a result of the piezoelectric device deforming to the first main surface side and a charge generated at a negative potential obtained as a result of the piezoelectric device deforming to the second main surface side when the plate-shaped piezoelectric device deforms. However, energy loss accompanying this movement of charges is generated in the full-wave rectifier circuit and, hence, there is a problem in that the ratio (energy efficiency) of available energy to generated energy is low.